Biologie und Biochemie der Fortpflanzung und ihre Beeinflussung

Abstract

Sarnen-und

Structure and conformation of a stoicheiometric adduct of 4-epimatricin with 3β-hydroxydihydrocostunolide and of 4-epimatricin alone

“…4-Epimatricin Alone.-The present investigation has confirmed the stereochemistry of (2) established by spectroscopic analysis2 The cycloheptene ring shows the C, chair conformation8 (Table 5 ) with a mirror plane through C (7) and the middle point of the double bond C(l)=C(lO). Despite the marked asymmetry of the substitution pattern of the cycloheptene ring, the deviation from the ideal C, symmetry is small as measured by the parameter8 C, = 8.4", and by the asymmetry parameters 6*7 AC,[C(7)] = O.O09 ( 1). The total puckering amplitude is Q = 0.672(3) A.…”

“…For the cyclopentene ring, both the deviation from 90" of (p2[ = 83(1)"] and the value of AC2[C(2)] [ =0.029 (1)] indicate a deviation from the ideal twist. The overall puckering, Q = 0.126(3) A, is not marked; C(4) and C(5) are at -0.071(3) and 0.076(3) A, respectively, from the mean plane through the ring.…”

“….0(4)", Q = 0.383(2) A, and with a C, plane through C(7), ACs[C(7)] = 0.024(1). The acetate group adopts the Z conformation with the carbonyl group and H(8) syn [H(8)-€(8b 0(4)-C(16) = -33(…”