Organic Chemistry of Drug Synthesis. Volume 7

O

tBuO 2 C +H^2 N BO tBuO 2 C

NH CO 2 H

160 161

NH

O

HN BO

O

N

N

O

HN BO

O

N

N

NH

O

162

164

IBuB(OH) 2

OH

HN B OH

O

N

N

NH

O

165

163

CO 2 H

A drug that inhibits HIV by binding with the specific receptor sites on
the immune system cells used by the virus to entry into the cells, mara-
viroc, was discussed in the preceding chapter. The chemical structure of
the inhibitoraplaviroc( 179 ), which acts by the same mechanism, is,
however, quite different from the drug discussed in Chapter 5. An enantio-
selective synthesis for the key starting amino acid starts with the oxidation
of the double bond in cyclohexyl acrylic ester ( 166 ) with potassium osmate
to afford the cis diol ( 167 ). Reaction of intermediate 167 with sulfuryl
chloride affords the cylic sulfate ester ( 168 ). Treatment of intermediate
168 with sodium azide leads to attack at the carbon bearing the carboxylate
group with inversion of configuration ( 169 ). Catalytic reduction followed

CO 2 C 2 H (^5) CO 2 C 2 H 5
CO 2 C 2 H 5
CO 2 C 2 H (^5) CO 2 C 2 H 5
166
[O]
167
OH
OH
SO 2 Cl 2
O
O SO^2
168
NaN 3
N 3
OH

1. H 2
   2.t-BOC 2 O

170

NHCO 2 tBu

OH

169

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