Johnson synthesis

An explosion has been reported with o-chloronitro compounds Rondestvedt Johnson Synthesis 1977,851. For a review of the use of hydrazine, see Futst Berio Hooton Chem. Rev. 1965, 65. 51-68, pp. 52-60. See also Yustc Saldana Walls Tetrahedron Lett. 1982, 23, 147 Adger Young Tetrahedron Lett. 1984, 25. 5219. 

For some other methods of accomplishing this conversion, see Rondestvedt Johnson Synthesis 1977. 850 Entwistle. Gilkerson Johnstone Telford Tetrahedron 1978,34, 213. 

The Johnson synthesis of steroids and triterpenes has been extended to a synthesis of d/-serratenediol (7), a pentacyclic triterpene with a seven-membered C ring and nine asymmetric centers. ... 

B. J. B. Johnson, Synthesis of a Nitrobenzeneboronic Acid Substituted Polyacrylamide and Its Use in Purifying Isoaccepting Transfer Ribonucleic-Acids, Biochemistry, 1981,20(21), 6103-6108. 

The use of trimethylsilyloxy derivatives, instead of other bases in the Hilbert-Johnson synthesis of nucleosides has resulted in better yields. Niedballa and Vorbriiggen have reported on the scope and limitations of this modified Hilbert-Johnson reaction. Thus, in the example shown in Scheme 120, stannic chloride in 1,2-dichloroethane was used to effect a... 

Optically active compds. A soln. of er butyllithium in pentane added at -78 under Ng to an ethereal soln. of n-butyl p-tolyl sulfoxide, and the product isolated after 0.5 hr. at -78° n-butyl er butyl sulfoxide. Y 76%. F. e. and procedures s. J. P. Lockard, C. W. Sdiroeck, and C. R. Johnson, Synthesis 1973, 485. 

S.D. Johnson, Synthesis of Digital Designs from Rcursion Equations, Cambridge, Massachusetts MIT Press, 1983. 

Consider the Johnson synthesis of progesterone. The q clization precursor (102) was derived from cyclopentenone 101, which was prepared by an intramolecular aldol-dehydration of 1,4-diketone 100. Johnson did not construct the 1,4-difunctional relationship present in 100. It was purchased in the form of 2-methylfuran (96). This simple heterocyclic compound is at the same oxidation state as the 1,4-dicarbonyl compound, released by hydrolysis of the furan, first in a protected form (98 and 99) and finally ready for use in the aldol dehydration (99 — 100). 

Bycroft, B. W., D. Cameron, A. Hassanali-Walji, and A. W. Johnson Synthesis of a Model Relating to the Chromophores of Capreomycin and Viomycin. Tetrahedron Letters 1969, 2539. 

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