7.7
[]. Richard J Duffy, et al. Asymmetric synthesis, structure, and reactivity of unexpectedly stable spiroepoxy-beta-lactones including facile conversion to tetronic acids: application to (+)-maculalactone A. J Org Chem. 29 Jul ;74():4772-8.
H5-H-H42-H42
P26-P264-P27-P27-P28-P2+P52-P62-P4+P2-P45-P5
GHS6
6.
28