A convenient preparation of the side-chain lactone ring of a withanolide precursor.
Condensation of C22 and C21 steroidal aldehydes with ethyl 4,6-dimethyl-2-oxo-2H-pyran-5-carboxylate 1 in alkaline medium, followed by decarboxylation, provides a simple route to the alpha, beta-unsaturated side-chain delta-lactone synthesis for a classical withanolide precursor.
Maione
A M
AM
Dipartimento di Studi Farmaceutici, Università La Sapienza, Roma, Italy.
Romeo
A
A
Casinovi
C G
CG
D000447:Aldehydes; D055598:Chemical Phenomena; D002621:Chemistry; D004875:Ergosterol / Q000031:analogs & derivatives*; D005977:Glutarates; D006878:Hydroxides; D011188:Potassium; D017680:Potassium Compounds; D011753:Pyrones; D054358:Withanolides
D000447:Aldehydes; D005977:Glutarates; D006878:Hydroxides; D017680:Potassium Compounds; D011753:Pyrones; D054358:Withanolides; C061917:3-methyl-2-pentenedioic acid ethyl ester; C010376:withanolide D; C061918:ethyl isodehydracetate; D011188:Potassium; C029943:potassium hydroxide; D004875:Ergosterol