Studies on the synthese of heterocyclic compounds. Part DXCV. The stereochemistry of methyl O‐(4‐hydroxy‐3‐methoxycinnamoyl)reserpate

Abstract

The stereochemistry of the title compound (1), which has an antihypertensive activity, was confirmed by chemical and spectroscopical evidences.

General methods of synthesis of indole alkaloids. 14. Short routes of construction of yohimboid and ajmalicinoid alkaloid systems and their carbon-13 nuclear magnetic resonance spectral analysis

“…These involvements of a hydrogen with a proximate electron pair are the consequence of the rigid ring system directing the electron pair orbital toward the hydrogen. The following represent illustrations of y shifts induced by hydrogen-bond interactions: the shielding of C(15) by C(2) and of C(21) by C(2) and C(6) in pseudoyohimbine (42a), 3-epi-a-yohimbine (44a), and reserpine (44b), as compared with yohimbine (41a), -yohimbine (43a), and isoreserpine (43d), respectively,52 and the shielding of (34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52) and epialloyohimbane (44e). Finally, the identity of the 27 ppm shift for C( 19) of alloyohimbane (43c) and C(5) of m.frans-perhydroanthracene (58),53 two substances of like overall conformation, shows the y effect of a nitrogen lone pair (57) to be equal to that of a carbon-hydrogen bond.…”