How can the following compounds be prepared using ethyne as the starting material?
a.

Predict the products of reaction of pent-1-yne with the following reagents.

j. NaNH₂

k. H₂SO₄/HgSO₄, H₂O

l. Sia₂BH, then H₂O₂, ^–OH

Draw the ketone(s) you would expect to form by treating the following alkynes under the conditions of hydroboration–oxidation: (a) 6-methyloct-1-yne, (b) 1,10-dicyclohexyldec-5-yne, and (c) 5-phenylhex-2-yne.

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For the alkynes shows here, show the product(s) expected to form when treated under the following conditions: (vii) 1. BH₃ 2. H₂O₂, NaOH. If you expect two products, show both.

(c)

Predict the product of the following aldehyde/ketone syntheses.

(c)

What are products of the following reactions?

e.

The following functional-group interchange is a useful synthesis of aldehydes.

(a) What reagents were used in this chapter for this transformation? Give an example to illustrate this method.

(b) This functional-group interchange can also be accomplished using the following sequence.

Propose mechanisms for these steps.

For each of the following alkynes, draw the products obtained from (1) the acid-catalyzed addition of water (mercuric ion is added for part a) and from (2) hydroboration–oxidation:

a. 1-butyne 

What is the major product of the reaction of 1 mol of propyne with each of the following reagents?

e. aqueous H₂SO₄, HgSO₄

f. R₂BH in THF followed by H₂O₂/HO⁻ /H₂O