Total Synthesis of (+)‐Machaeriols B and C and of Their Enantiomers with a Cannabinoid Structure |
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| Authors: | Hee Jin Lee Yong Rok Lee Sung Hong Kim |
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| Affiliation: | 1. School of Chemical Engineering and Technology, Yeungnam University, Gyeongsan 712‐749, Korea, (phone: +82‐53‐810‐2529;2. fax: +82‐53‐810‐4631);3. Analysis Research Division, Daegu Center, Korea Basic Science Institute, Daegu 702‐701, Korea |
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| Abstract: | An efficient and concise synthesis of the biologically interesting (+)‐machaeriol B ( 2 ) and its enantiomer 5 was accomplished from O‐phenylhydroxylamine ( 7 ) in four steps (Scheme 2). In addition, the first total synthesis of natural (+)‐machaeriol C ( 3 ) and its enantiomer 6 was achieved from the readily available ester 15 in eight steps (Scheme 4). The key strategies in the syntheses of 2 and 5 involved benzofuran formation through a [3,3]‐sigmatropic rearrangement and trans‐hexahydrodibenzopyran formation by a domino aldol‐type/hetero‐Diels–Alder reaction. In the case of 3 and 6 , the key steps were stilbene formation by a Horner–Wadsworth–Emmons reaction and trans‐hexahydrodibenzopyran formation by domino reactions. |
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| Keywords: | Machaerium multiflorum (+)‐Machaeriols B and C Cannabinoids [3,3]‐Sigmatropic rearrangement Aldol reaction Hetero‐Diels– Alder reaction Horner– Wadsworth– Emmons reaction |
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