What is 2 Corinthians in relation to 1 Corinthians?

Second Corinthians is Paul's follow-up letter to First Corinthians. While First Corinthians was largely a letter of reproof and correction rather than commendation, Second Corinthians continues that correspondence, with Paul defending his apostleship against snide remarks and attacks coming from Corinth.

Les teaches that in Corinthians, Paul is following up his first letter. First Corinthians was a letter of reproof and correction, not a letter of commendation for the most part. Second Corinthians is a follow-up letter, and Paul is first and foremost defending his apostleship because of all the snide remarks coming out of Corinth. Those remarks were attacking the apostles, and Paul was heartbroken by some of the things being spoken about him. The study picks up in 2 Corinthians chapter 2, continuing the line of thinking about the gentleman who caused so much grief in 1 Corinthians chapter 5.

How does Paul's list of sufferings in 1 Corinthians 4 compare to 2 Corinthians?

Paul's list in 1 Corinthians 4 is much the same as the sufferings and persecutions he lists in 2 Corinthians. Both portray apostolic weakness and hardship: being fools for Christ, hungry, thirsty, naked, buffeted, homeless, reviled, persecuted, defamed, and treated as the world's filth and offscouring.