328571-01-3

Upstream product

• 2385-77-5 (R)-Citronellal 
• 1117-61-9 (3R)-citronellol 
• 98-09-9 benzenesulfonyl chloride 

Downstream Products

• 328570-87-2 (1R,3aS,4S,7aR)-1-((R)-1,5-Dimethyl-hexyl)-4-[2-(5-methoxy-2-methyl-phenyl)-ethyl]-7a-methyl-octahydro-inden-5-one 
• 328570-91-8 (1R,3aS,4S,5R,7aR)-4-(5-methoxy-2-methylphenethyl)-7a-methyl-1-((R)-6-methylheptan-2-yl)-octahydro-1H-inden-5-ol 
• 328570-89-4 (1R,3aS,4S,7aR)-1-((R)-1,5-Dimethyl-hex-4-enyl)-4-[2-(5-methoxy-2-methyl-phenyl)-ethyl]-7a-methyl-octahydro-inden-5-one 
• 328570-85-0 (1R,7aR)-1-((R)-1,5-Dimethyl-hex-4-enyl)-4-[2-(5-methoxy-2-methyl-phenyl)-ethyl]-7a-methyl-1,2,3,6,7,7a-hexahydro-inden-5-one 
• 126210-14-8 Astrogorgadiol 

Relevant academic research and scientific papers

Synthesis of (-)-astrogorgiadiol

Astrogorgiadiol is a naturally occurring Vitamin D analogue that, in cell culture, downregulates the production of the cytokine osteopontin (OPN). OPN has been implicated in virulent asthma, and OPN knockout mice do not develop osteoporosis. As we have pursued whole animal studies with astrogorgiadiol, we have increased the scale of the synthesis. We report an improved preparation of the A-ring synthon and the scale-up of the diasteromerically pure D-ring/sidechain chiron.

Synthesis of (-)-astrogorgiadiol

Reaction of Rh2(S)-PTPA4 with the (R)-citronellol-derived α-diazo-β-ketoester 1 led to the formation of cyclic β-ketoester 2 in 95% yield and 48% diastereomeric excess. The purity of 2 was increased to >99% de after one crystallization. To demonstrate its utility in steroid total synthesis, the β-ketoester 2 was carried on to secosteroid (-)-astrogorgiadiol (3), a naturally occuring vitamin D analogue with antiproliferative properties.