This dissertation, titled "Steric Effects in Organic Chemistry," is divided into two parts. Part I focuses on the chemistry of di-t-butylketene, including its preparation and reactions with various reagents such as formaldehyde, acetaldehyde, acetone, and others. The study explores the steric effects of the t-butyl groups on the reactivity of di-t-butylketene, demonstrating that it is highly hindered and only reacts under specific conditions, such as with formaldehyde in the presence of a catalyst. The research also attempts to synthesize various derivatives of di-t-butylketene, including cyclopropanones and allene oxides, but finds that these compounds are not easily formed or isolated. Part II investigates the alkaline hydrolysis of substituted methyl benzoates, examining how substituents affect the rate of hydrolysis. The study shows that certain substituents, such as the formyl group, significantly enhance the hydrolysis rate by participating in the reaction mechanism. The research includes the preparation of various acids and esters, as well as the experimental investigation of their hydrolysis rates. The findings highlight the importance of steric and electronic effects in determining the reactivity of organic compounds.This dissertation, titled "Steric Effects in Organic Chemistry," is divided into two parts. Part I focuses on the chemistry of di-t-butylketene, including its preparation and reactions with various reagents such as formaldehyde, acetaldehyde, acetone, and others. The study explores the steric effects of the t-butyl groups on the reactivity of di-t-butylketene, demonstrating that it is highly hindered and only reacts under specific conditions, such as with formaldehyde in the presence of a catalyst. The research also attempts to synthesize various derivatives of di-t-butylketene, including cyclopropanones and allene oxides, but finds that these compounds are not easily formed or isolated. Part II investigates the alkaline hydrolysis of substituted methyl benzoates, examining how substituents affect the rate of hydrolysis. The study shows that certain substituents, such as the formyl group, significantly enhance the hydrolysis rate by participating in the reaction mechanism. The research includes the preparation of various acids and esters, as well as the experimental investigation of their hydrolysis rates. The findings highlight the importance of steric and electronic effects in determining the reactivity of organic compounds.