Totalsynthese optisch aktiver Steroide. XIII. Mitteilung. Synthese von 4,9(11)‐Androstadien‐3,17‐dion

Abstract

PreEog zum 70. Geburtstag gcwidmet (11. 2. 76) XIII. Mitteilung [l]Synthesis of 4,9(11)-androstadiene-3,17-dione. -Sui~zmary. The total synthesis of 4,9(11)-androstadienc-3,17-dione (23) is dcscribcd starting from (1 S , 7aS)-l-l-butoxy-7a-methyl-5,6,7,7a-tetrahydroindan-5-onc (8) as a CY-building block. The key step involves alkylation ot 8 with l-chloro-7,7-o-phenylenedioxy-octane-3-one (14) a novel AB-synthon t o givc the diketone 15. 15 is converted to the secosteroid 20 via the diene enol ether 17 using a previously dcscribcd procedure. Low temperature mcthylation of 20 affords predominantly the 10P-methyl compound 21, which is readily transformed into the title dione 23.

An Efficient and Convenient Method for Preparation of 2,2-Disubstituted and 2-Monosubstituted 1,3-Benzodioxoles from Ketones and Aldehydes with Catechol Catalysed by ZrO2/SO42-

“…1,3-Benzodioxole derivatives are widely employed for the protection of catechols compounds in multistep organic syntheses. [1][2][3][4][5] They were also applied as pesticides or pesticide intermediates, [6][7][8] herbicides, 9 antioxidants, 10,11 antimicrobial 12 and medicinal. 13,14 The acetal ring is stable to a variety of commonly used reagents such as HNO 3 , 15 Pb(OAc) 4 16 and BuLi 17 , and is cleaved by NaI-AcCl, 18 boron tribromide, 19 and NaN(SiMe 3 ) 2 or Li(i-Pr).…”