Some Transformations of Adducts of 3,6-Dimethoxy-4,5-methylenedioxy-1,2-didehydrobenzene and Furans. An Approach to the 5,8-Dimethoxy-6,7-methylenedioxynaphtho[2,3-c]furan-4,9-dione Ring System of Ventilone A

Adducts derived from the aryne 3,6-dimethoxy-4,5-methylenedioxy-1,2-didehydrobenzene (19) with furan and 2-methoxyfuran have been converted into 5,8-dimethoxy-6,7-methylenedioxy-1,2-naphthoquinone (22) and 5,8-dimethoxy-6,7-methylenedioxy-1,4-naphthoquinone (24) respectively. The trapping of (19) with 1H,3H-furo[3,4-c]furan (38) yielded an unstable adduct (37), which on acid-catalysed ring opening and subsequent oxidation was transformed into 5,8-dimethoxy-6,7-methylenedioxynaphtho[2,3-c]furan-4,9-dione (36), a compound possessing the ring system of the naturally occurring quinone ventilone A.

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Resolving the Mystery of Ring Opening in the Synthesis of Benzo[d][1, 3]oxazin-4-one and Quinazolin-4(3H)-one

Letters in Organic Chemistry ◽

10.2174/1570178616666181217114030 ◽

2019 ◽

Vol 16 (11) ◽

pp. 898-905

Author(s):

Harun Patel ◽

Rahul Pawara ◽

Sanjay Surana

Keyword(s):

Characteristic Feature ◽

Ring Opening ◽

Biological Activities ◽

Heterocyclic Ring ◽

Ring System ◽

Time Saving ◽

Fusion Strategy ◽

Good Template ◽

Lead Generation

Quinazoline is the six-membered heterocyclic ring system reported for its versatile biological activities. This characteristic feature of quinazoline makes it a good template for a lead generation library. Ring opening is one of the major concerns in the synthesis of quinazolin-4(3H)-one that results in diamide formation. Here, alternative fusion strategy is reported, which is a time-saving and costeffective method to overcome the ring opening problem associated with the synthesis of benzo[ d][1,3]oxazin-4-one and quinazolin-4(3H)-one.

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Rigid diol bearing 6-6-6 fused ring system derived from naturally occurring myo -inositol and its polyaddition with diisocyanates

Journal of Polymer Science Part A Polymer Chemistry ◽

10.1002/pola.28765 ◽

2017 ◽

Vol 55 (22) ◽

pp. 3798-3803 ◽

Cited By ~ 3

Author(s):

Arata Yoshida ◽

Atsushi Sudo

Keyword(s):

Ring System ◽

Naturally Occurring ◽

Fused Ring ◽

Fused Ring System

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Asymmetric total synthesis of paecilomycin C through intramolecular nucleophilic ring opening of an epoxide

Organic & Biomolecular Chemistry ◽

10.1039/c9ob01504c ◽

2019 ◽

Vol 17 (31) ◽

pp. 7369-7379 ◽

Cited By ~ 3

Author(s):

Joy Chakraborty ◽

Samik Nanda

Keyword(s):

Total Synthesis ◽

Ring Opening ◽

Asymmetric Total Synthesis ◽

Naturally Occurring ◽

Acid Lactone ◽

Nucleophilic Ring Opening

An efficient asymmetric total synthesis of naturally occurring resorcylic acid lactone (RAL) paecilomycin C was achieved by employing carboxylate assisted 5-exo-tet ring opening of an epoxide as a key reaction.

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Asymmetric total synthesis of cryptoconcatone I

Organic & Biomolecular Chemistry ◽

10.1039/c9ob00399a ◽

2019 ◽

Vol 17 (14) ◽

pp. 3552-3566 ◽

Cited By ~ 1

Author(s):

Ranjan Kumar Acharyya ◽

Pratik Pal ◽

Shrestha Chatterjee ◽

Samik Nanda

Keyword(s):

Total Synthesis ◽

Late Stage ◽

Ring Opening ◽

Epoxide Ring ◽

Asymmetric Total Synthesis ◽

Epoxide Ring Opening ◽

Cascade Cyclization ◽

Naturally Occurring

An efficient asymmetric total synthesis of naturally occurring γ-Z-butenolide cryptoconcatone I was achieved by employing substrate-directed reductive epoxide ring opening and late-stage “Pd–Cu” catalyzed cascade cyclization.

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ChemInform Abstract: MINOR AND TRACE STEROLS IN MARINE INVERTEBRATES. 31. ISOLATION AND STRUCTURE ELUCIDATION OF 23H-ISOCALYSTEROL, A NATURALLY OCCURRING CYCLOPROPENE. SOME COMPARATIVE OBSERVATIONS ON THE COURSE OF HYDROGENOLYTIC RING OPENING OF STEROIDAL

Chemischer Informationsdienst ◽

10.1002/chin.198310323 ◽

1983 ◽

Vol 14 (10) ◽

Author(s):

L. N. LI ◽

H. LI ◽

R. W. LANG ◽

T. ITOH ◽

D. SICA ◽

...

Keyword(s):

Ring Opening ◽

Structure Elucidation ◽

Marine Invertebrates ◽

Naturally Occurring

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ChemInform Abstract: SYNTHESIS OF 5-AMINO-9-(β-D-RIBOFURANOSYL)-V-TRIAZINO-(4,5-B)PYRIMIDO(4,5-D)PYRROL-4-ON# E AND UNUSUAL RING OPENING OF THIS NEW RING SYSTEM WITH THE VILSMEIER-HAACK REAGENT

Chemischer Informationsdienst ◽

10.1002/chin.198044312 ◽

1980 ◽

Vol 11 (44) ◽

Author(s):

F. L. CHUNG ◽

R. A. EARL ◽

L. B. TOWNSEND

Keyword(s):

Ring Opening ◽

Ring System

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Carbon–nitrogen bond cleavage of pyridine with two molecular substituted allenoates: access to 2-arylpyrimidin-4(3H)-one

Chemical Communications ◽

10.1039/c8cc08946a ◽

2018 ◽

Vol 54 (100) ◽

pp. 14128-14131 ◽

Cited By ~ 2

Author(s):

Tao Jin ◽

Hongdong Yuan ◽

Shikuan Su ◽

Xueshun Jia ◽

Chunju Li ◽

...

Keyword(s):

Benzene Ring ◽

Ring Opening ◽

Pyridine Ring ◽

Bond Cleavage ◽

Ring System ◽

Nitrogen Bond

A DABCO-catalyzed annulation reaction of pyridin-2-amine and substituted allenoates enables the ring-opening of a pyridine ring system and the formation of two new rings including a pyrimidinone ring and a benzene ring.

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