The p−toluenesulfonate shown undergoes an intramolecular Williamson reaction on treatment with base to give a spirocyclic ether. Demonstrate your understanding of the terminology used in the preceding sentence by writing the structure, including stereochemistry, of the product.

The following compound may be synthesized through alkylation of an appropriate enamine with an alkyl bromide, followed by hydrolysis of the resulting immonium ion. Using this strategy, provide the necessary starting materials for the synthesis.  Draw the necessary enamine below.

Give the suitable synthesis to accomplish the following transformation.

1. Bicyclic keto compounds such as camphor react predictably with nucleophiles according to steric influences; this effect has been termed steric approach control. In contrast, the reaction of nucleophiles with simple acyclic and monocyclic keto compounds are influenced primarily by thermodynamic factors; this effect has been termed product development control. Given the following reaction, predict the identity of the major product and provide a rationale for your selection. ОН NABH4 t-Bu. t-Bu t-Bu. ELOH 1 2

Chemistry Please help explain this textbook question: Although N, N -dimethylaniline is extremely reactive toward electrophilic aromatic substitution and is readily substituted by weak electrophiles, such as diazonium and nitronium ions, this reactivity is greatly diminished by the introduction of an alkyl substituent in an ortho position.

If pentane-1,3-diol reacts with in the presence of pyridine it gives product A. And if A reacts with in the presence of pyridine it gives a product B. Indicate which products A and B are.

Provide the structure of the two organic product(s) which results when 2-bromo-2-methylbutane is treated with sodium ethoxide.

2. Intramolecular aldol cyclization of 3,3-dimethyl-2,5-nonanedione with aqueous NaOH yields a mixture of two enone products in the approximate ratio 9:1. Write their structures and show how each is formed.

For each reaction, give the expected substitution product, and predict whether the mechanism will be predominantly first order (SN1) or second-order (SN2). (a) isobutyl bromide + sodium methoxide