Desaminogirollines syn 2'S,3'S and 2'R,3'R have been prepared from N1-camphosulfonamide 4-carboxaldehyde imidazole and their diastereoisomeric derivatives have been separated. The stereoselective synthesis of chiral natural girolline has been achieved from D(-)arabinose: this ose is condensed with formamidine acetate to obtain a 4(5)-[1',2',3'-trihydroxypropyl]-imidazole; the side-chain is chlorinated before being aminated via an azido compound and the 2-amino group of girolline is obtained by rhodium catalytic reduction of the 2-diazo derivative.
prepared in an enantiomerically pure form by reduction of dl-ketone with respective (+)- and (−)-Darvon-LiAlH4 complex followed by purification with the aids of esterification with d- and l-menthoxyacetyl chlorides and (−)-camphanic acid chloride, respectively. Absoluteconfiguration of naturally occurring (+)-mayol and (+)-cembrenene was determined by correlation with enantiomerically pure compounds
General Scope of 1,4-Diastereoselective Additions to a 2(3<i>H</i>)-Quinazolinone: Practical Preparation of HIV Therapeutics
作者:Nicholas A. Magnus、Pat N. Confalone、Louis Storace、Mona Patel、Christopher C. Wood、Wayne P. Davis、Rodney L. Parsons
DOI:10.1021/jo0263162
日期:2003.2.1
The practical and highly diastereoselective syntheses of CF3-substituted dihydroquinazolinones via 1,4-additions of nucleophiles to chiral auxiliary substituted 2(3H)-quinazolinones is described. This methodology is applied to the syntheses of the NNRTIs (nonnucleoside reverse transcriptase inhibitors) DPC 961 (1) and DPC 083 (2), which are useful for the treatment of HIV (human immunodeficiency virus). The synthesis of DPC 961 (1) requires three steps, proceeds in >55% overall yield from the keto-aniline 9, and gives synthetic access to DPC 083 (2). In addition, the scope of the new diastereoselective 1,4-addition chemistry is investigated. The first preparation of DPC 961 (1) described in this paper is a derivatization fractional crystallization protocol.
Glycosyl-inositol derivatives I. Synthesis of 1-substituted chiro-inositol derivatives
作者:Frank Tagliaferri、Wang Sho-Nong、William K Berlin、Robert A Outten、T.Y Shen